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Author Topic: MLA-30 Loop antenna  (Read 8188 times)

Matt285

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MLA-30 Loop antenna
« on: October 21, 2019, 1149 UTC »
Please let me know about your experiences with the MLA-30 antenna. I've seen a lot of positive reviews so far, but would love to hear first hand opinions.

Matt285

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Re: MLA-30 Loop antenna
« Reply #1 on: October 22, 2019, 0013 UTC »
Im having trouble copying a link for some reason. 'Youtube' MLA-30 VS W6LVP loop.

Offline JimIO

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Re: MLA-30 Loop antenna
« Reply #2 on: October 22, 2019, 0228 UTC »

Matt285

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Re: MLA-30 Loop antenna
« Reply #3 on: October 22, 2019, 1257 UTC »
Thanks for posting the link.

Offline NJQA

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Re: MLA-30 Loop antenna
« Reply #4 on: October 23, 2019, 1205 UTC »
The schematic was reverse engineered here:

https://www.g8jnj.net/activeantennas.htm#MLA30

I havenít been that impressed by it other than the low price.  The ďpower isolatorĒ actually has an inverter in it to raise the 5 volts up to something higher.  I question the wisdom of putting a switching noise generator there! 

I might try it with a conventional power isolator at 12 volts to see if it works any better.

Matt285

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Re: MLA-30 Loop antenna
« Reply #5 on: October 24, 2019, 0025 UTC »
I find it amazing that no one on this whole forum owns one of these antennas. I have received several emails now from first hand purchasers who are very pleased with the product. Yes, i'm sure that it has some faults if you look for them hard enough, but I feel like most have nothing to say because their just lurkers without any opinion or they've already purchased a Wellbrook or W6LVP and can't bare the fact that they paid 10 times more for what they got in comparison to a product that is much more affordable. Its a shame that people can't get off their high horse and admit that there is an affordable option that would greater their listening experience.

Offline NJQA

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Re: MLA-30 Loop antenna
« Reply #6 on: October 24, 2019, 1134 UTC »
I have one.  And I also have a Wellbrook.  I havenít given it a thumbs up or thumbs down because I havenít compared them side by side, in the same location.  My initial impression is that it seems noisy, but that was with it inside the house, so you canít draw conclusions yet.

But my comments still stand.  The price is low.  And I donít like their approach to providing power.  Putting a switcher right at the bias-t is nuts.  My own unit started having problems with the LED intermittently operating.  The schematic showed it is driven directly off of the switcher, so I suspect the switcher has failed.

There are a lot of choices out there for loop antennas - Wellbrook, DXE, Pixel, MFJ, and W6LVP to name a few.  The price for these tend to run in the $250 to 450 range.  For that money you get a huge step up in both the electronics and in the mechanical construction.

Everything about the MLA30 is cheap.  To sell at a $30 price point it has to be.  I seriously doubt it would last more than a year or two exposed to the weather.  If you look at G8JNJís posting, you can see that the circuit has some serious design mistakes.  I fully expect that the parts inside the unit are chinese counterfeits.  They would have to be at this price point.  I suspect the plastic enclosure will turn brittle when exposed to sunlight.  This is not something built for the long term.

That being said, there are uses for a $30 antenna, so it has its niche.  Just realize it isnít in the same class as the other loops.  It may be good enough for your particular situation.  Or not.

Offline ChrisSmolinski

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Re: MLA-30 Loop antenna
« Reply #7 on: October 24, 2019, 1311 UTC »
While I do not own an MLA-30, nor a Wellbrook, from the posts I have seen about them (the SDR-Radio mailing list recently had an excruciatingly long thread) by those who have used and compared them, the MLA-30 is not comparable to either a Wellbrook or LZ1AQ loop. Even without testing them, basic economics suggests this is going to be the case.

That's not to say that the MLA-30 or W6LVP may not be useful for some DXers.  Maybe they were using the whip antenna on the radio or a random piece of wire laying on the floor in the shack previously. An inexpensive active loop is likely to be better than that, especially if it is now outside. To a large extent the antenna(s) to use depends on your location and situation. You may not have the room for a larger/better antenna. Many DXers unfortunately live in high RFI environments. If your noise floor is huge, it probably does not matter what you use for an antenna.

I am fortunate to live in an RF quiet rural area, with enough land for large, full sized, passive antennas. I did have an LZ1AQ based loop for some time and was impressed with the performance for the size of the antenna. But it does not come close to the performance of my full sized passive antennas, nor do I expect it would for anyone who is not noise floor limited. That's why I never bought a Wellbrook, Pixel, or similar high-end loop, they won't be of any use for me. FWIW the loop in question now functions as a passive loop (I have sensitive enough SDRs that I can make use if it that way) and it is useful in some situations such as on MW where the directivity is a benefit.
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Offline Ray Lalleu

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Re: MLA-30 Loop antenna
« Reply #8 on: October 24, 2019, 2052 UTC »

 I suspect the plastic enclosure will turn brittle when exposed to sunlight.


Just give it one or two coats of paint. (A general idea for any plastic part not intended for outdoor use)
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Offline Josh

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Re: MLA-30 Loop antenna
« Reply #9 on: October 24, 2019, 2129 UTC »
I was looking at one for a few months now and was undecided between it and the parts kit W6 loop, if they put a switcher in the feed, no way, this is rfi-ing your anti-rfi antenna by design. When you have a linear dc psu you might get 60cps or 120cps ripple, but not much else unless it's very poorly designed or sickly, but with a switcher you get harmonics ewevery 16-100kc or so thru hf.

 I wonder if Smolinksi Heavy Industries will ever roll out a diy active loop, say just the feed block and head unit, user supplies/builds loop element and coax, with the head unit having decent sn and dynamic range.
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Matt285

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Re: MLA-30 Loop antenna
« Reply #10 on: October 24, 2019, 2312 UTC »
In hindsight I realize my post was a bit accusatory and aggressive. The biggest thing I wanted to get out was that why can't we embrace more affordable ways of bettering our hobby in particular, not just for the people that have been involved for many years, but for the people that are new to it. We all have the same goal of keeping this alive. Yes as I said in reference to the MLA-30 .There are no perfect products(especially the cheap ones) but I love the feedback negative or otherwise. Its all about starting a talking point. Lets put our brains together and find a way to improve such products. There are so many great minds in this community. I would also like to say that a big part of my discouragement is due to seeing so many empty comments vs the views. yes Ive done this for a long time, but just because a newer person post a comment about a catch we've gotten many times, it doesn't mean that  we need to ignore them. Let's be more encouraging to these people. Most all of us remember the magic of our first 'cool' catch. It only takes a few key strokes to acknowledge them of their strides of listening for hours to experience  that joy. Don't just ignore post because they may seem mundane . Take a minute and expound and give tips. It goes a long ways

Offline jasmine

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Re: MLA-30 Loop antenna
« Reply #11 on: October 27, 2019, 0554 UTC »
Please let me know about your experiences with the MLA-30 antenna. I've seen a lot of positive reviews so far, but would love to hear first hand opinions.

hi, though i am new at this hobby i've gotten pretty good results it seems with the MLA-30. i'm a college student so space was at a premium when thinking about antennas (previously i had an indoor longwire lol). anyway i was looking into loops and decided to give the MLA-30 a try as it was in my budget range.

anyone can look at my loggings in the Utility forum to see some of my results with it from my Seattle, WA location.
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Offline Josh

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Re: MLA-30 Loop antenna
« Reply #12 on: October 27, 2019, 2207 UTC »
See? It works well enough. However, it could be better if they got rid of the switcher and allowed perhaps some gain adjustment, or tuned the chip to increase dynamic range. As I recall in one test it beat the other loop as it could null deeper, wich in some cases is why people buy or make loops to begin with. If it's Jasmine approved it's good enough for me.
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Matt285

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Re: MLA-30 Loop antenna
« Reply #13 on: October 27, 2019, 2331 UTC »
Im not sure how accurate it is, but I've heard the deeper nulling is due to using a thinner wire. I'm gonna get one for sure. If nothing else it should be a great portable antenna for easy set up. It will be a few weeks since I had to shell out for $140.00 on Halloween costumes. (3 Kids) I will definitely post the results and comparison to my 135' OCF dipole.

Offline ChrisSmolinski

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Re: MLA-30 Loop antenna
« Reply #14 on: October 28, 2019, 1014 UTC »
It will be a few weeks since I had to shell out for $140.00 on Halloween costumes. (3 Kids)

You should have bought a loop antenna for each of them to wear as part of a robot costume.
Chris Smolinski
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netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree